package 剪绳子;

import java.util.Scanner;

public class Main {
    static int N = 100010, n, m;
    static int[] len = new int[N];

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        n = in.nextInt();
        m = in.nextInt();
        for (int i = 0; i < n; i++) {
            len[i] = in.nextInt();
        }
        double l = 0, r = 1e9;
        while (r - l > 1e-4) {
            double mid = (l + r) / 2;
            if (check(mid)) {
                l = mid;
            } else {
                r = mid;
            }
        }
        System.out.printf("%.2f", l);
    }

    private static boolean check(double length) {
        int s = 0;
        for (int i = 0; i < n; i++) {
            s += len[i] / length;
            if (s >= m) {
                return true;
            }
        }
        return false;
    }
}
